How to solve the problem of low grid voltage?

Solution 1 (Adjustment of Existing System)

1.1. First, adjust the tap changer of the distribution transformer to the appropriate position. Typical power transformers have ±2.5*3 adjustable taps on the high-voltage side.

2.1. Adjust the three-phase load of the distribution transformer appropriately (load current is related to voltage drop and line loss rate).

3.1. Increase the cross-sectional area of ​​some conductors (resistance is related to voltage drop and line loss rate).

Solution 2 (Addition of Voltage Stabilizer and Other Devices)

2.1. High-Power Automatic Voltage Stabilizer

This voltage stabilizer uses compensation regulation technology to linearly regulate the output voltage. Even with input voltage deviations of ±30%, it can still stably output the rated voltage (400V, 440V, 480V, etc.). It is easy to use and suitable for most power supply environments.

2.2. Synchronous Condenser

This device utilizes under-excitation operation to provide active power to the grid and absorb reactive power. When the grid voltage is low, over-excitation operation provides reactive power to raise the grid voltage.

2.3 Reactive Power Compensation Devices

These include random compensation, device-specific compensation, and tracking compensation. By improving the power factor of the power grid, they reduce the total load current and voltage drop in the lines, thus increasing the voltage at the end of the grid.

2.4 Increasing the Tap Range of Distribution Transformers

Increasing the tap range of distribution transformers directly increases the grid voltage, meeting the voltage requirements of user equipment during the day. However, at night, when user loads are light, the voltage at the end of the grid approaches the transformer output voltage, leading to excessively high voltage that cannot be automatically adjusted.

2.5 Energy Storage Systems

Energy storage systems operate in grid-connected mode, maintaining synchronization with the voltage and frequency of the power grid lines. They provide power during peak load periods and absorb power during off-peak periods. This method can flexibly compensate for low grid voltage, but its cost is several times higher than other solutions. The working principles and applications of these five new devices for low voltage compensation will be described in detail later.